2016 FAQs: The Alternative to Leylandii

Persistent controversy was not the reason we took the decision during 2016 to recommend Western Red Cedar as the far better alternative to Leylandii.

Why the Alternative is Needed

The reason we recommend an alternative to Leylandii has nothing to do with the problems it causes when planted inappropriately – we trust our customers not to be so inconsiderate – but because of the increasing, and increasingly damaging, presence of Cinara cupressi – the sap-sucking Cypress aphid. And while, as its name suggests, it will attack a few other conifers, Leylandii is its main target and is the cause of foliage fatally turning brown.

The symptoms are clearly visible and first manifest themselves in summer when shoots start to yellow. By late summer, yellow will start to turn brown and many of the infected branches will already be dead having succumbed to the drying effect of the aphid’s attention. The affected plants may also be coated with a powdery, sooty mould.

Of course, gardening is a constant battle against pests and diseases, but, according to the criteria used by the International Union for the Conservation of Nature it is one of the world’s 100 worst invasive alien species – it originated in the Middle East.

This is not a problem we take lightly, particularly as the 1km perimeter of our own nine-acre nursery is delineated by a Leylandii hedge consisting of some 500 2m+ plants.

This illustrates part of the danger specific to Leylandii – it is often planted on a grand scale so although some systemic insecticides (Scotts Bug Clear Ultra, Bayer Garden’s Ultimate Bug Killer…) can be effective if applied in time and then reapplied every six weeks, such treatment is neither practical nor, frankly, affordable when faced with a hedge of significant proportions.

And it gets worse. Affected branches will not reshoot and all one can do is cut them out and then train the neighbouring branches to cover up the gap, hoping that they have not also been affected.

So, while those of us who planted Leylandii many years ago can do little except keep our fingers crossed, those who haven’t yet taken the plunge can choose the alternative hedge option– The Western Red Cedar (Thuja plicata) …

The Advantages of Western Red Cedar

No hedging plant grows faster than Leylandii (75cm – 90cm a year) but Western Red Cedar is no slouch (45cm – 60cm per year). In all other regards, Western Red Cedar is the superior alternative as it:

• Can be maintained to any height and to a width as narrow as 45cm
• Is easy to maintain and extremely forgiving…
• When trimming, and unlike Leylandii, you can cut into the old wood – it won’t brown and will re-shoot
• Will grow in any well-draining soil, even shallow chalk
• Prefers full sun, but will grow happily, if a little less quickly, in full shade
• Makes an exceptionally smart, formal hedge when tightly clipped. While a similar hedge can be achieved with Leylandii, it requires a great deal more work
• Has a delightful aromatic fragrance, described by many as subtle pineapple
• The foliage is equally attractive – spreading, sometimes drooping, in a display of rich olive greens
• Even its bark is striking – its rich, dark, browny-red shreds to add texture and contrast to the warm, forest colours of the foliage
• Has an RHS AGM

View Our Recommended Hedges